21281147289 has 24 divisors (see below), whose sum is σ = 31200305760. Its totient is φ = 13976206848.

The previous prime is 21281147273. The next prime is 21281147297. The reversal of 21281147289 is 98274118212.

21281147289 is a `hidden beast` number, since 21 + 2 + 81 + 1 + 472 + 89 = 666.

It is not a de Polignac number, because 21281147289 - 2⁴ = 21281147273 is a prime.

It is a super-2 number, since 2×21281147289² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21281147089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 110649 + ... + 234105.

It is an arithmetic number, because the mean of its divisors is an integer number (1300012740).

Almost surely, 2^21281147289 is an apocalyptic number.

It is an amenable number.

21281147289 is a deficient number, since it is larger than the sum of its proper divisors (9919158471).

21281147289 is a wasteful number, since it uses less digits than its factorization.

21281147289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123749 (or 123746 counting only the distinct ones).

The product of its digits is 129024, while the sum is 45.

It can be divided in two parts, 212811 and 47289, that added together give a square (260100 = 510²).

The spelling of 21281147289 in words is "twenty-one billion, two hundred eighty-one million, one hundred forty-seven thousand, two hundred eighty-nine".